Automated Geospatial Watershed Assessment (AGWA) Tool

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INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE

The Automated
Geospatial Watershed
Assessment Tool

What is AGWA?

More than 80 percent of our
freshwater comes from watersheds.
Watersheds collect water from
various sources, like rain, snow
and runoff that drains into nearby
waterways, such as lakes, streams
and rivers. Land use in our nation's
watersheds is complex and varied,
ranging from crop production areas
to rangelands, pastures, forests,
meadows and urban areas. How
we manage the activities that take
place on watersheds influences
the quantity and quality of water
available for domestic, industrial,
agricultural and ecological uses.

EPA, U.S. Department of
Agriculture - Agricultural
Research Services (USDA-ARS),
and the University of Arizona
co-developed the Automated
Geospatial Watershed Assessment
(AGWA) tool to help manage and
analyze water quantity and quality.
AGWA utilizes two watershed
models, the Kinematic Runoff and
Erosion (KINEROS2) hydrologic
model and the Soil and Water
Assessment Tool (SWAT), to
evaluate small to large, complex
watersheds with varying soils, land
uses and management conditions,
and their related environmental and
economic impact.

Using basic, easily attainable
geographic information systems
(GIS) data, AGWA provides a

simple, direct, and repeatable
methodology for hydrologic model
setup, execution, and visualization.

KINEROS2:

The KINEROS2 model is an event-
oriented, physically-based model
used to describe the processes of
interception, infiltration, surface
runoff and erosion from small
watersheds dominated by overland
flow. KINEROS2 can be used
to determine effects of various
artificial features, including urban
development, small detention
reservoirs, various low-impact
development methods, and lined
channels on flood hydrographs and
sediment yield.

SWAT:

SWAT is used to predict the impact
of land management practices on
water, sediment and agricultural
chemical yields in large, complex
watersheds with varying soils, land
use and management conditions
over long periods of time (> 1 year).

How AGWA works:

AGWA conducts hydrologic
modeling and runoff assessments
at multiple temporal and spatial
scales. The tool provides a visual
display of results, and information
that can help decision-makers
identify potential problem
areas that may need additional
monitoring or mitigation actions.
AGWA can generate alternative
future land-use/cover scenarios
and display differences between
simulation outputs (potential
change) designed to provide
decision support when combined
with planning efforts.

AGWA Tool Applications:

In 2013, a wildfire burned over
130,000 acres east of Boise, Idaho.
Nearly 75 percent of the burned
area had moderate to high burn
severity, threatening the ecosystem
and the regions' water. The U.S.
Department of Interior (DOI)
National Burn Area Emergency
Response (BAER) team used


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AGWA to help develop emergency
stabilization plans that identified
potential threats to people, wildlife
and land from post-fire flooding
and erosion. The BAER team
estimated that approximately $7-8
million was saved by using AGWA
to target 2,000 acres for treatment
instead of the initial 16,000 acres
identified through more traditional
methods. Since 2011, AGWA has
been used by BAER teams on over
20 wildfires.

AGWA has also been used in a
variety of other projects:

•	Analyzing land impacts of coal
bed methane extraction;

•	Supporting management of
impacts from military training
activities;

•	Evaluating flow in intermittent
and ephemeral streams

on military bases in the
southwestern U.S.;

•	Assessing connectivity of
ephemeral streams for Clean
Water Act applications;

•	Aiding in development of
watershed protection plans (e.g.
Best Management Practices);
and

•	Evaluating relative non-point
source pollution (Clean Water
Act, Sec. 319).

AGWA versions:

Three versions of AGWA are
available:

•	AGWA 1.5 for Environmental
Systems Research Institute
(ESRI) Arc View 3.x

•	AGWA 2.x for ESRI ArcGIS

9.x

•	AGWA 3 X for ESRI ArcGIS

10.x

System Requirements:

AGWA requires Microsoft
Windows, an internet connection
and the following downloads:

•	Environmental Systems
Research Institute (ESRI)*
ArcGIS 10.x, ArcGIS 9.x or
Arc View 3.x

•	AGWA add-in/extension,
which includes the AGWA user
interface and functionality to set
up the models

•	AGWA Directory, which
includes the KINEROS2 and
SWAT models

•	GIS data

•	Digital Elevation Model

•	Raster land cover/land use
map

•	Soil data

•	Optional precipitation data

Download AGWA

AGWA example datasets, training
exercises and documentation can
be downloaded free of charge:
www, tucson. ar s. ag. gov/agwa

EPA's AGWA resource page:

www, epa. gov/water-research/

automated-geospatial-watershed-

assessment-tool

Media Contact:

Emily Smith

smith. emilv @epa. gov

Technical Contacts:

William Kepner
kepner.william@epa.gov

March 2016


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